Circulating units for paint preheaters



Feb. 7, 1961 L. BECK 2,970,813

CIRCULATING UNITS FOR PAINT PREHEATERS Filez'` June 5. 1957 1NVENT0R. 0a/5 Bic/f /7 TTORNEY UnitedStates Patent O Fce CIRCULATING UNITS FOR PAINT PREHEATERS This invention relates to paint preheaters, generally of the type and kind disclosed in my prior application Seri-al Number 477,551, filed December 24, 1954, issued in Patent No. 2,802,089, granted August 6, 1957. More particularly, the invention deals with a paint circulating unit for preheaters of this type and kind. Still more particularly, the invention deals with a circulating unit, wherein detachment of a fitting element, including the intake circulating pipe, will facilitate cleaning of the unit from time to time.

Further, the invention deals with a multiple finned sleeve for forming circulating passages directly exposed to the radiation of heat through said fins for highly eiiicient operation of the preheater.

The novel features of the invention will be best under stood from the following description, when taken together with the accompanying drawing, in which certain embodiments of the invention `are disclosed and, in which, the separate parts are designated by suitable reference characters in each of the views and, in which:

Fig. l is a broken side and sectional View of a circulating unit made according to my invention, indicating, in part in dot-dash lines, the preheatercasing or housing, in which the unit is arranged; and

Fig. 2 is a section on the line 2 2 of Fig. 1.

In practice, I provide a unit comprising a body part 11, generally of hexagon cross-sectional form, the body part having an upwardly directed short tubular extension 12, suitably fixed and secured within the heater casing or housing, which is indicated, in part, in dot-dash lines at 13.

Considering my prior application, above identified, the casing of the preheater also includes an outer wall of insulation in order to maintain the heat within the casing, but, as my invention deals simply with the circulating unit, all detail reference to the preheater is eliminated in order to simplify the showing.

The body 11 is generally tubular in form and has a circulating chamber 14, the lower end of which isinternally threaded, as seen at 15, to detachably receive a fitting head or element 16. The element 16 has an externally threaded portion 17 mounted in the threaded portion of the body 11, as clearly seen at the right of Fig. l. The portion 17 terminates in an upwardly extended reduced portion 18 internally threaded to receive a long circulating pipe or tube 19, which becomes part of the element 16 insertable into and removable from the body 11, particularly in cleaning the unit from time to time.

Outwardly of the portion 17 is a generally circular enlarged portion 20, having flattened sides, one of which 2,970,813 Patented Feb. 7, 1961 as the intake fitting; whereas, the fitting 24 is the recirculating fitting. With these fittings are coupled flexible tubes, through which paint is introduced into the unit through the fitting 23 and, whenever desired and when the discharge gun of preheaters of this type and kind is not in operation, the paint can be re-circulated by passage through the fitting 24 and the tube, not shown, which is coupled therewith.

The pipe 19 is mounted in the other single passage of the Y passage 22, as will be apparent. Mounted and seated within the extension 12 of the body 11 is an elongated tube 25, in which is fitted a finned sleeve 26. The sleeve '26 extends to a position short of the upper end of the tube 25 and seats against a closure disc or plate 27 fitted in the tube 25, as noted at the top of Fig. 1 of the drawing.

The sleeve 26 has a plurality of circumferentially spaced long inwardly directed fins 2S and short inwardly directed fins 29. The long fins 28 extend radially inwardly to a point seating upon the tube 19; whereas the short fins 29 terminate short of the tube 1.9, as clearly illustrated in Fig. 2 of the drawing. 'It will, thus, be seen that heat from the heater casing 13 not only heats the Wall of the sleeve 26, but also will radiate heat through the long hns 28 to heat the tube 19 and these radiating fins 28 and 29 also serve to heat the paint circulating downwardly through the sleeve 26 upon being discharged from the upper end of the tube 19, this circulating being illustrated by the arrows in Fig. 1. The paint enters the element 16 through the intake fitting 23, and, then, passes up through the tube 19.

Mounted in one side of the body 11 is a discharge pipe 30, which communicates with the circulating chamber 14. All of the passages in the sleeve 26 open into the chamber 14, as will clearly appear from a consideration of Fig. 1, so that the heated paint is free to pass through the discharge pipe 30 and extend to the usual gun for 'applying the paint to a surface, it being understood that a exible tube is also coupled with the end portion of the pipe 30, as with other devices of this type and kind.

It will appear from a consideration of Fig. l of the drawing that the upper end 19' of the tube 19 terminates short of the closure disc or plate 27 for free discharge of the paint passing upwardly through the tube into the passages formed between the fins 23, which passages are sub-divided to an extent by the fins 29, as will be apparent from a consideration of Fig. 2.

In addition to the attachment and detachment of the element 16 with respect to the body 11 in cleaning the unit, in some instances, the entire unit can be removed from the heater casing 13 without in any way disturbing the structure features of this unit. In other words, the discharge pipe 30 is positioned beyond the limits of the casing 13, different in this respect from the illustration in my prior application, hereinbefore identified.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A circulating unit for paint preheaters, said unit comprising a tubular body portion having a threaded bore opening through one end, a fitting element arranged within and in threaded engagement with said bore and including an inlet fitting for introduction of paint into said element, an elongated intake pipeV coupled with said element and through which paint is adapted to be circulated, a discharge pipe coupled with the body portion and communicating with the circulating chamber in said body and around the base of said pipe, an elongated tube mounted in and extending beyond the upper end of said body portion, a closure for the upper end of said tube, a radiating sleeve arranged snugly in said tube around and widely spaced from said intake pipe, said sleeve extending to said closure and having inwardly extending long-A and short radiating fins, the long fins extending to and engaging the surface of said intake pipe, and said ns forming, around the intake pipe and within said sleeve, a plurality of circulating passages opening into theA circulating chamber of said body portion for discharge through said discharge pipe.

2. A circulating unit as defined in claim 1 wherein said body portion is hexagon in cross-sectional form, and said fitting element having flattened sides, facilitating rotation of the element in attachment and detachment of the element with respect to said body portion.

3. A circulating unit as defined in claim 1 wherein the fins of said sleeve extend the full length thereof.

References Cited in the le of this patent UNITED STATES PATENTS Schmitz Feb. 27, Doble Dec. 16, Mott June 5, Lehane et al. Mar. 27, Jantsch Dec. 19, Brown Aug. 18, Roswell f, r, r ...,v Apr. 12,

FOREIGN PATENTS SwedenV Apr. 2, 

